Ford Motor Company, the assignee of this application, did not conduct a novelty study on this subject matter in the U.S. Patent Office. Therefore, we are unaware of any prior art which may be on file in the U.S. Patent Office that may be relevant to the subject matter of this application.
We are aware, however, that a general discussion has been undertaken in the literature proposing chemically regenerable redox fuel cells in which a catholyte solution is oxidized directly to its oxidized state by oxygen gas and an anolyte solution is reduced directly to its reduced state by direct action of a reducing agent such as carbon (A.M. Posner, Fuel 34 330 (1955)). However, in these reports, we are unaware of any discussion of any practical working cell using aqueous electrolytes in which the direct action of oxygen and hydrogen are used to regenerate solutions used in the redox fuel cell.
A redox fuel cell in which the catholyte solution can be directly regenerated by the action of oxygen gas and the anolyte solution similarly can be directly regenerated by the action of hydrogen gas is a highly desirable fuel cell. Such a redox fuel cell could be termed an indirect hydrogen/oxygen fuel cell, as hydrogen and oxygen are the only two chemical ingredients to be chemically spent in generating the electric power from the fuel cell. The catholyte solution and anolyte solution remain functionally intact and continue in operation for as long as one desires to operate the redox fuel cell. Since this approach avoids an expensive catalyzed three-phase conventional electrode, the cost of operating such a fuel cell is kept at a minimum, while the efficiency thereof remains high.
Since the catholyte and anolyte solutions are regenerated respectively by the action of oxygen and hydrogen thereon, such regeneration may take place at a location spaced away from the fuel cell and at a different temperature from the fuel cell, thus permitting relatively simple and unsophisticated equipment to construct the fuel cell itself and associated equipment.
It is a principal object of this invention to provide a chemically regenerable redox fuel cell in which the oxidant is oxygen and the fuel is hydrogen, and in which the oxidant is directly exposed to the catholyte solution in order to regenerate the same, while the hydrogen is exposed directly to the anolyte solution to regenerate the same.